Method for separating tantalum-niobium smelting slag

Abstract

The invention provides a method for separating tantalum-niobium smelting slag. The method comprises the following steps of water leaching pretreatment, screening classification, cassiterite reselection and enrichment and high-strength magnetic separation of rare earth. Wherein in the water leaching pretreatment, tantalum-niobium smelting slag and water are mixed according to the liquid-solid ratio of (1-7): 1, stirring is performed at the temperature of 0-30 DEG C, and water leaching slag and filtrate are obtained through separation; and the particle size of the screening and grading is 38-74 microns. Soluble impurities are fully dissolved and separated through low-temperature water leaching, and interference of the soluble impurities on the follow-up sorting effect is avoided; the materials are split according to particle size differences in the screening and grading process, so that the coarse and fine particle materials are matched with optimal gravity separation equipment respectively, and density separation of cassiterite and rare earth ore can be achieved more easily; cassiterite extraction is achieved by means of density difference during reselection and enrichment of cassiterite, rare earth ore is accurately separated through high-strength magnetic separation by means of magnetic difference, and separation of all processes is more sufficient. In addition, the separation method is a physical beneficiation method and is low in cost, simple, environmentally friendly and friendly to the environment.

Description

Technical Field

[0001] This invention relates to the field of resource recycling technology, and specifically to a method for separating tantalum-niobium smelting slag. Background Technology

[0002] Tantalum and niobium, as important rare metals, play an irreplaceable role in high-end fields such as electronics, aerospace, and metallurgy, primarily derived from the smelting and processing of tantalum and niobium concentrates. During the smelting process of tantalum and niobium concentrates, whether using pyrometallurgical methods (such as carbothermic reduction and aluminothermic reduction) or hydrometallurgical methods (such as acid leaching and alkali fusion), a large amount of smelting waste (hereinafter referred to as "tantalum and niobium smelting waste") is generated. According to industry statistics, approximately 8-12 tons of smelting waste are generated for every ton of tantalum and niobium produced. This waste not only contains incompletely recovered tantalum and niobium but also is enriched with tin, rare earth elements, and various valuable elements such as iron and aluminum, making it a typical polymetallic solid waste.

[0003] Currently, the industry has developed some conventional treatment methods for the recovery and utilization of polymetallic residues from tantalum and niobium smelting, such as acid-base enrichment, reduction-oxidation enrichment, chlorination, and direct hydrofluoric acid leaching. However, these methods still have significant limitations in practical applications, making it difficult to achieve efficient and comprehensive utilization of resources.

[0004] Patent CN119822419A discloses a method for treating tantalum-niobium tailings using a hydrofluoric acid-sulfuric acid process. This method employs steps such as dilute sulfuric acid leaching, iron powder reduction, cooling crystallization, and chemical precipitation, with the primary objective of recovering iron and fluorine. However, this method has significant limitations. Its process design is entirely focused on dissolved components, failing to effectively enrich and recover valuable components such as cassiterite and rare earth elements that exist as independent mineral phases in the tailings, resulting in resource waste.

[0005] In view of this, it is necessary to design an improved method for separating tantalum-niobium smelting slag in order to solve the above problems. Summary of the Invention

[0006] In view of the technical problems existing in the background art, the present invention provides a method for separating tantalum and niobium smelting slag, which aims to solve the problem that valuable components such as cassiterite and rare earth elements existing in the tailings as independent mineral phases cannot be effectively enriched and recovered.

[0007] This invention provides a method for separating tantalum-niobium smelting slag, comprising the following steps: S1, Water leaching pretreatment: Tantalum-niobium smelting slag is mixed with water, stirred, and after reaction, solid-liquid separation is performed to obtain water-leached slag and filtrate; S2, Screening and Grading: The water-leached residue obtained in step S1 is screened and graded to obtain the oversize and undersize material. S3, Reselection of cassiterite-enriched cassiterite: S31, the material over the screen is sent to a coarse gravity separation device for separation to obtain cassiterite concentrate A and gravity tailings I; S32, the undersize material is fed into a fine-grained gravity separation device for separation to obtain cassiterite rough concentrate B and gravity tailings II; S4, high-intensity magnetic separation for rare earth elements: S41, the gravity separation tailings I are fed into a strong magnetic separation device, and under the action of a magnetic field, they are separated to obtain magnetic rare earth rough concentrate C and non-magnetic cassiterite rough concentrate E. S42, the gravity separation tailings II are fed into a high-intensity magnetic separator, and separated under the action of a magnetic field to obtain magnetic rare earth rough concentrate D and non-magnetic cassiterite rough concentrate F.

[0008] As a further improvement of the present invention, in step S1, when the tantalum-niobium smelting slag is mixed with water, the liquid-to-solid ratio is 1-7:1.

[0009] As a further improvement of the present invention, in step S2, the particle size of the sieving and grading is 38-74 μm.

[0010] As a further improvement of the present invention, in step S1, the water immersion temperature is 0-30°C.

[0011] As a further improvement of the present invention, in step S1, the stirring speed is 200-400 rpm.

[0012] As a further improvement of the present invention, in step S1, the reaction time is 30-90 min.

[0013] As a further improvement of the present invention, in step S31, the coarse particle gravity separation device is a shaking table, the stroke of the shaking table is 4-12mm, and the number of strokes is 400-800 times / min.

[0014] As a further improvement of the present invention, in step S32, the fine particle gravity separation equipment is a centrifugal concentrator or a blanket concentrator, the centrifugal force of the centrifugal concentrator is 50-200G, the speed of the blanket concentrator is 0.5-2m / s, and the feed concentration during mineral processing is 20%-30%.

[0015] As a further improvement of the present invention, in steps S41 and S42, the strong magnetic separation equipment is a vertical ring high gradient magnetic separator, and the feed concentration of tailings I and II is 20%-30% during mineral processing.

[0016] As a further improvement of the present invention, in steps S41 and S42, the magnetic field strength is 0.8-1.6T.

[0017] Compared with the prior art, the beneficial effects of the present invention are: The present invention provides a method for separating tantalum and niobium smelting slag, namely, a process of "low-temperature water leaching pretreatment - screening and classification - gravity separation enrichment of cassiterite - strong magnetic separation of rare earth elements", which processes the tantalum and niobium smelting slag in stages. Low-temperature water leaching fully dissolves and removes soluble impurities, avoiding their interference with subsequent separation effects; screening and classification separates the material according to particle size differences, allowing coarse and fine particles to be adapted to the optimal gravity separation equipment, making it easier to achieve density separation of cassiterite and rare earth ores; gravity separation enrichment utilizes density differences to extract cassiterite. High-intensity magnetic separation utilizes magnetic differences to precisely separate rare earth ores, resulting in more thorough separation in each process. This reduces the impurity content in subsequent cassiterite and rare earth concentrate purification steps, improves purification efficiency, reduces purification difficulty, and facilitates precise separation of cassiterite and rare earth concentrates, thereby improving their quality. Specifically, the grade of cassiterite concentrate is ≥20% and its recovery rate is ≥93%, while the grade of rare earth concentrate is ≥33% and its recovery rate is ≥80%.

[0018] The method for separating tantalum and niobium smelting slag according to the present invention is a physical mineral processing method, which is environmentally friendly and meets the requirements of green metallurgy and circular economy.

[0019] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0020] To more clearly illustrate the technical solution of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0021] Figure 1 This is a process flow diagram of the method for separating tantalum and niobium smelting slag in the embodiments of this application. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0024] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0025] Please see Figure 1 As shown, the present invention provides a method for separating tantalum-niobium smelting slag, comprising the following steps: S1, Water leaching pretreatment: Tantalum-niobium smelting slag is mixed with water, stirred, and after reaction, solid-liquid separation is performed to obtain water-leached slag and filtrate; Specifically, when tantalum and niobium smelting slag is mixed with water, the liquid-to-solid ratio is 1-7:1, the water immersion temperature is 0-30℃, the stirring speed is 200-400rpm, and the reaction time is 30-90min.

[0026] S2, Screening and Grading: The water-leached residue obtained in step S1 is screened and graded to obtain the oversize and undersize material. Specifically, the particle size for sieving and grading is 38-74 μm.

[0027] S3, Reselection of cassiterite-enriched cassiterite: S31, the material over the screen is sent to a coarse gravity separation device for separation to obtain cassiterite concentrate A and gravity tailings I; S32, the undersize material is sent to the fine particle gravity separation equipment for separation to obtain cassiterite rough concentrate B and gravity tailings II; Specifically, the coarse-grained gravity separation equipment is a shaking table with a stroke of 4-12 mm and a stroke rate of 400-800 times / min. The fine-grained gravity separation equipment is a centrifugal concentrator or a blanket concentrator with a centrifugal force of 50-200G and a speed of 0.5-2m / s. During mineral processing, the feed concentration is 20%-30%.

[0028] S4, high-intensity magnetic separation for rare earth elements: S41, the gravity separation tailings I are fed into a strong magnetic separation device, and under the action of a magnetic field, they are separated to obtain magnetic rare earth rough concentrate C and non-magnetic cassiterite rough concentrate E. S42, the gravity separation tailings II are fed into a high-intensity magnetic separator, where they are separated under the action of a magnetic field to obtain magnetic rare earth rough concentrate D and non-magnetic cassiterite rough concentrate F.

[0029] Specifically, the high-intensity magnetic separation equipment is a vertical ring high-gradient magnetic separator. The magnetic field strength of the high-intensity magnetic separation is 0.8-1.6T, the addition rate of tailings I and II is 0.3-0.5m / s, and the feed concentration of tailings I and II during mineral processing is 20%-30%.

[0030] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0031] Example 1 The tantalum-niobium smelting slag produced by wet leaching and extraction of tantalum-niobium concentrate is used as raw material, with a tin (Sn) grade of 5.2% and a total rare earth oxide (REO) content of 6.8%.

[0032] This embodiment provides a method for separating tantalum-niobium smelting slag, and its process flow diagram is shown below. Figure 1 As shown, the specific steps include the following: S1, Water leaching pretreatment: Tantalum and niobium smelting slag and water are mixed at a liquid-solid ratio of 5:1, with 1000 kg of tantalum and niobium smelting slag and 5000 L of water. The temperature is controlled at 15℃ and the stirring speed is maintained at 250 r / min. The reaction is carried out for 90 min. After the reaction, a plate and frame filter press with a filtration area of ​​20 m² and a filter cloth pore size of 5 μm is used for solid-liquid separation to obtain 350 kg of water-leached slag and 5640 L of filtrate. S2, Screening and grading: The water-leached residue obtained in step S1 is screened and graded. The water-leached residue is fed into a linear vibrating screen (the screen material is stainless steel woven mesh, and the grading particle size is 38μm (400 mesh)). The vibration frequency is controlled at 35Hz and the amplitude is 1.5mm for grading and screening, resulting in 100kg of oversize material and 250kg of undersize material. S3, Reselection of cassiterite-enriched cassiterite: S31, 100 kg of the oversize material is fed into an XCT-1100 shaking table, with a stroke controlled at 10 mm and a stroke rate of 300 times / min. Deionized water is used as the rinsing water (rinsing water volume 12 L / min) for gravity separation. Under the action of gravity, cassiterite, due to its high density, settles to the concentrate end of the shaking table, yielding 30 kg of cassiterite rough concentrate A (tin grade 39.5%) and 70 kg of gravity separation tailings I. S32, 250 kg of the screened material is fed into a TC-300 blanket mill, with the blanket speed controlled at 0.3 m / s and the feed concentration at 20% (mass fraction). Deionized water is used as the rinsing water (rinsing water flow rate 5 L / min) for gravity separation. Under the action of gravity and blanket transmission, fine-grained cassiterite adheres to the surface of the blanket and is discharged with it, yielding 100 kg of cassiterite rough concentrate B (tin grade 31.2%) and 150 kg of gravity separation tailings II. S4, high-intensity magnetic separation for rare earth elements: S41, 70 kg of gravity separation tailings is fed into an ISLon-1000 vertical ring high gradient magnetic separator. The magnetic field strength is controlled at 1.5T, the feed concentration is 30% (mass fraction), and the feed speed is 0.5 m / s for magnetic separation. The separation yields 30 kg of magnetic rare earth concentrate (39.2% rare earth oxide grade) and 40 kg of non-magnetic cassiterite concentrate. S42, 150 kg of gravity separation tailings II is fed into a SLon-1000 vertical ring high gradient magnetic separator of the same model. The magnetic field strength is controlled at 1.5T, the feed concentration is 30%, and the feed speed is 0.5 m / s. The separation process yields 50 kg of magnetic rare earth concentrate D (rare earth oxide grade 27.1%) and 100 kg of non-magnetic cassiterite concentrate F.

[0033] Examples 2-4 and Comparative Example 1 Examples 2-4 and Comparative Example 1 respectively provide a method for separating tantalum-niobium smelting slag. The difference from Example 1 is that the liquid-solid ratio in step S1 is different, as shown in Table 1. The other steps are roughly the same as in Example 1 and will not be described again here.

[0034] Table 1 Results of tantalum-niobium smelting slag separation in Examples 1-4 and Comparative Example 1 Comparative Example 2 Comparative Example 2 provides a method for separating tantalum-niobium smelting slag. The difference from Example 1 is that in step S2, the particle size selected for screening the water-leached slag is 90 μm. The other steps are roughly the same as in Example 1 and will not be repeated here.

[0035] The tin grade of cassiterite concentrate A obtained from Comparative Example 2 was 12%, the tin grade of cassiterite concentrate B was 11%, the tin grade of nonmagnetic cassiterite concentrate E was 12%, the tin grade of nonmagnetic cassiterite concentrate F was 11%, the rare earth oxide grade of rare earth concentrate C was 14%, and the rare earth oxide grade of rare earth concentrate D was 15%. The total recovery rate of cassiterite concentrate was ≥65%, and the total recovery rate of rare earth concentrate was ≥66%.

[0036] As shown in Table 1, the tin grade of cassiterite concentrate A obtained in Examples 1-4 of this invention is 20%-27%, the tin grade of cassiterite concentrate B is 21%-30%, the tin grade of non-magnetic cassiterite concentrate E is 20%-23%, the tin grade of non-magnetic cassiterite concentrate F is 20%-22%, the rare earth oxide grade of rare earth concentrate C is 33%-41%, and the rare earth oxide grade of rare earth concentrate D is 40%-52%. The total recovery rate of cassiterite concentrate is ≥93%, and the total recovery rate of rare earth concentrate is ≥85%. The total recovery rate of cassiterite concentrate obtained in Comparative Example 1 is 92.77%, and the total recovery rate of rare earth concentrate is 74.38%. The results of Examples 1-4 and Comparative Examples 1-2 show that the cassiterite concentrate obtained by the method of this invention has a grade (≥20%) and recovery rate (≥93%), and a rare earth concentrate grade (≥33%) and recovery rate (≥80%). The present invention achieves a high overall recovery rate for cassiterite and rare earth concentrates. The separation method of this application reduces the difficulty of purification and facilitates precise separation of cassiterite and rare earth concentrates, thereby improving their quality.

[0037] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A method for separating tantalum niobium smelting slag, characterized by, The method comprises the following steps: S1, water immersion pretreatment: tantalum niobium smelting slag is mixed with water, stirred, and after reaction, solid-liquid separation is performed to obtain water immersion slag and filtrate; S2, screening classification: the water immersion slag obtained in step S1 is subjected to screening classification to obtain oversize and undersize; S3, gravity separation and tin stone enrichment: S31, the oversize is fed into a coarse particle gravity separation device for separation to obtain tin stone coarse concentrate A and gravity separation tailings I; S32, the undersize is fed into a fine particle gravity separation device for separation to obtain tin stone coarse concentrate B and gravity separation tailings II; S4, high-intensity magnetic separation of rare earth: S41, the gravity separation tailings I are fed into a high-intensity magnetic separation device, and under the action of a magnetic field, separation is performed to obtain magnetic rare earth coarse concentrate C and non-magnetic tin stone coarse concentrate E; S42, the gravity separation tailings II are fed into a high-intensity magnetic separation device, and under the action of a magnetic field, separation is performed to obtain magnetic rare earth coarse concentrate D and non-magnetic tin stone coarse concentrate F.

2. The method of separating tantalum niobium smelting slag according to claim 1, characterized in that, In step S1, when the tantalum niobium smelting slag is mixed with water, the liquid-solid ratio is 1-7:

1.

3. The method of separating and extracting tantalum and niobium smelting slag according to claim 1, characterized in that, In step S2, the particle size of the screening classification is 38-74 μm.

4. The method of separating tantalum niobium smelting slag according to claim 1, characterized in that, In step S1, the water immersion temperature is 0-30 ℃.

5. The method of separating tantalum niobium smelting slag according to claim 1, characterized in that, In step S1, the stirring speed is 200-400 rpm.

6. The method of separating tantalum niobium smelting slag according to claim 1, characterized in that, In step S1, the reaction time is 30-90 min.

7. The method of separating tantalum niobium smelting slag according to claim 1, characterized in that, In step S31, the coarse particle gravity separation device is a shaking table, the stroke of the shaking table is 4-12 mm, and the stroke frequency is 400-800 times / min.

8. The method of separating tantalum niobium smelting slag according to claim 1, characterized in that, In step S32, the fine particle gravity separation device is a centrifugal concentrator or a carpet machine, the centrifugal force of the centrifugal concentrator is 50-200 G, and the speed of the carpet machine is 0.5-2 m / s; when the ore is concentrated, the ore concentration is 20%-30%.

9. The method of separating tantalum niobium smelting slag according to claim 1, characterized in that, In steps S41 and S42, the high-intensity magnetic separation device is a vertical ring high-gradient magnetic separation machine; when the ore is concentrated, the ore concentration of the tailings I and II is 20%-30%.

10. The method of separating tantalum niobium smelting slag according to claim 9, characterized in that, In steps S41 and S42, the magnetic field strength is 0.8-1.6 T.

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